Winder drum arrangement



July 23, 1963 R. s. WASHBURN WINDER DRUM ARRANGEMENT Filed Dec. 25, 1960 T E AM P m m INVENTOR. Ember) 61 M ashburn BY a r ATT RNEYS United States Patent 3,ti98,6l9 WKNDER DRUM ARRANGEMENT Robert S. Washhurn, lleloit, Wis, assignor to Beioit Iron Worlrs, Beloit, Wis, a corporation of Wisconsin Filed Dec. 23, 19nd, Ser. No. 78,173 7 Claims. (til. 24-2-66) The instant invention relates to winding devices, and more particularly, to an improved winder drum structure or arrangement.

Although the instant invention may be useful in a number of fields involving the winding of a traveling sheet upon itself, it is particularly useful in the paper winding field. In the conventional paper winding device, a traveling paper web is wound (usually first upon a core and) upon itself to form a wound paper roll. As the term is used herein, a wound paper roll is a roll formed by the winding of the traveling paper web upon itself at any stage during the windup process, from the paper roll initially formed by the first few wraps of the traveling sheet about a core to the completely wound roll at the end of the windup process. During the windup process, the wound roll, of course, becomes increasingly rnore heavy.

In the conventional windup device, the wound roll is continuously supported by a pair of underwinder drums. These drums are rotatably mounted rigid cylindrical members adapted to support the rather substantial load of the relatively more resilient Wound roll. A drum supports its share of this load along a limited area or line of contact between the drum and the wound roll. The underwinder drums often carry the entire weight of the wound roll during the entire windup process. There is thus an in creasingly greater load applied by the wound roll to the underwinder drums during the windup. An additional complication usually results from the fact that one of the underwinder drums is driven so as to effect driving of the wound roll during the windup process. These various factors have led to an undesirable lack of uniformity in the winding tightness of the wind in the case of relatively large diameter wound rolls. In order to solve the problem thus created, various prior workers in the art have proposed devices for acting upon the core during windup to relieve some of the load created by the great weight of the wound rolls near completion of the windup.

The instant invention, in contrast, affords a unique and relatively simple winding arrangement which is adapted to reduce the effect of variation in the Weight of the wound roll during windup so as to minimize lack of uniformity in the wound roll.

The instant invention provides a device for winding a traveling sheet upon itself to form a wound roll, that comprises a plurality of spaced underwinder drum assemblies adapted to support the wound roll from beneath, at least one of said assemblies comprising a pair of closely spaced uniplanar rollers and mounting means maintaining such uniplanar rollers in a plane generally tangential to said Wound roll during windup of the sheet, whereby the area supporting the weight of the wound roll via said pair of rollers is increased beyond that of the normal line of contact between a single underwinder drum and the wound roll.

It is, therefore, an important object of the instant invention to provide an improved and simple device for effecting a more uniform tightness in wound rolls of substantial diameter. The instant invention makes this improvernent possible by using in place of a conventional winder drum a pair of closely spaced rollers, which are so closely spaced that they effectively expand the so-called line of contact between a conventional underwinder drum and a wound roll. Moreover, this pair of rollers is preferably wrapped by a belt for purposes of maintenance "ice of an arc of contact for supporting the wound roll along the entire area between the two rollers. The assembly formed by this pair of rollers (with or without a covering belt) is mounted so as to take the place of a single underwinder drum without altering the manner of feeding the web into the wound roll.

Other and further objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed disclosure and the drawings attached hereto and made a part hereof.

On the drawings:

FIGURE 1 is an essentially diagrammatic elevational view of a winding device of the prior art;

FIGURE 2 is an enlarged fragmentary elevational view of the underwinder drum assemblies embodying the instant invention; and

FIGURE 3 is an enlarged fragmentary view of another underwinder drum assembly of another embodiment of the instant invention.

As shown in the drawings:

Referring to FIGURE 1, which shows a winding arrangement of the prior art, indicated generally by the reference numeral 10, it will be seen that the arrangement 10 comprises a partially wound roll of paper 11, wherein the traveling paper sheet 11a has been wound first upon a core 12 and then upon itself to form the wound roll 11. The wound roll 11 is supported from beneath by underwinder drums 13 and 14, which carry the entire weight of the wound roll 11 during the windup process. The in coming traveling sheet 11a passes around the bottom of the underwinder drum 14 upwardly between the underwinder drums 13, 14 and into a nip N-l between the wound roll 11 and the underwinder drum 14.

As the size of the wound roll it increases, it will be appreciated that the pressures at the nips N-1 and N-?; between the roll 11 and the underwinder drums 14 and 13, respectively, become quite substantial. Since the wound roll 11 is substantially cylindrical and the underwinder drurm 13 is also cylindrical, it will be understood that there is theoretically a line of contact L-2 between these two cylindrical members 11, 13 along which (approximately but not necessarily) one-half of the entire weight of the wound roll 11 is carried. Likewise, there is theoretically a line of contact L-l between the other underwinder drurn 14 and the wound roll 11, along which the remainder of the weight of the wound roll 11 is carried. Of course, with the very substantial weights here involved and the relative resilience in the wound paper moll 11, these so-called lines of contact L-1 and L2 are really relatively narrow areas of contact for practical purposes. Nevertheless, these areas are so narrow that there is created during the windup process a pressure wave in the (region of these lines of contact L-l, L-Z, herein indicated at P-l and P2. The pressure wave results from the sudden application of substantial force to the surface portions of the wound roll 1-1 at the instant they pass over one of the lines of contact L1 or L-Z. A study of these pressure waves P4, P4. has revealed that their net result is to effect a tightening of the wind of the paper along the outer portions of a wound roll as it increases in size.

It will be appreciated that the drawings herein show substantial spacing between the underwinder drum units (e.g. the drums 13, 14) for purposes of presenting the subject matter in diagrammatic views that are uncomplicated by crowding. As a matter of fact, however, the underwinder drums l3 and 14, would have to be spaced so closely together that the core 12 could be retained in a nip therebetween during the startup of the winding process. As here shown these underwinder drums (and the others hereinafter described) are shown spaced apart 3 to a greater extent for simplification in presenting the instant subject matter.

To funther simplify the presentation of the pressure wave concept, let us assume first that we are at an initial stage in the windup with only ten wraps or thicknesses of paper sheet around the core 12. At this time we will assume the total weight of the Wound roll 11 to be ten units, with a force equal to five units of weight being applied against the ten wraps of paper along the line of contact L-Z. This force has a given compacting effect or pressure wave effect against the Wound roll 11 which we shall assume extends through the entire ten Wraps of paper web on the core 12. This compacting and tightening effect will be funther complicated along the line of contact L-1 because of the feeding of the paper web 11a into this nip N1, and further because of the driving forces which may be applied to the underwinder drum 14. In fact, the tightening effect upon the outer wrap of 'the web is brought about to a substantial extent at the nip N1 wherea-t the incoming web is wound into the roll 11; but for purposes of simplification herein only the compacting effect at the other line of contact L-2 will be considered. Next, we can assume that the wound roll 11 has increased in size to the extent that instead of the initial ten wraps of paper web on the core 12 there are now 100 wraps. Disreganding the radius of the core, this would mean that the radius of the wound roll 11 had been increased by approximately a factor of 10, and the weight would accordingly be increased by the square of this factor, or 100 times, thus giving a total weigh-t of 1000 units. In this 1situation,the pressure wave P-Z created in the wound roll 11 at the region of the line of contact L2 with the underwinder drum 13 is created by the application of a force equivalent to one half of the weight of the roll, or 500 units :of weight. The net compacting effect at the pressure wave P-Z, however, will not be transmitted through the entire 100 wraps of web back to the core 12. Instead, this compacting effect will be absorbed in the somewhat resilient outer portion of the wound roll 11, and perhaps only the outer or wraps of the web. As a consequence, a tighter wind is obtained in the outer regions of the wound roll 11.

During the foregoing, we have referred to the theoretical line of contact L-2 as a substantially constant concept. As a matter of fact, it is initially a very narrow area extending on either side of the theoretical line, and it increases somewhat in area as the much greater pressures become involved. This is because of the yield or resilience in the paper roll 11; but this slight increase in the area .of contact along the line L-Z is not directly proportional to the increases in the load at this region. Thus, when the load is increased by the factor of 100 in the situation previously assumed, the area of contact along the 'line L-Z may be increased several fold, but 7 nothing comparable to the 100 fold that the load has been increased. After a careful study of the nature of the pressure wave and its effect upon lack of uniformity in the wind up of large diameter rol-ls, it has been found that there are substantial advantages in providing means for greatly increasing the area of contact, or the area carrying the load of the wound roll 11. It is believed that this improvement results from the fact that there may be no appreciable undesirable compacting or tightening of the outer regions of a wound paper roll 11 along a region of con-tact (e.g. L2), unless a certain minimum pressure ioad is applied to create a pressure wave (e.g. P-Z). This is based upon a concept of a minimum pressure or force per unit area which may be necessary to create an undesirable compacting situation. If means are provided for greatly increasing the overall area of contact, in accordance with the teachings of the instant invention, then the tendency for the creation of undesirable pressure waves by the generation of extremely high forces per given unit of area is decreased, since a substantially greater area is provided for purposes of supporting the total weight of the wound roll 11.

Referring now to FIGURE 2 which shows an embodiment of the instant invention indicated (generally by the reference numeral 20, it will be seen that there is shown fragmentarily a wound roll 21 wherein a traveling paper web 21a is wrapped about a core (not shown) and upon itself in the conventional manner. The wound roll 21 is supported by two underwinde-r drum assemblies indicated generally at 23 and 24. The traveling web 21a passes beneath the right hand assembly 24 and into a twindup nip N-4 between the :driven underwinder drum assembly 24 and the wound roll 21.

The .underwinder drum assemblies 23 and 24 are maintained in spaced relationship for supporting the total Weight of the wound roll 241 in a manner similar to the way in which conventional under-winder drums 13, 14 support a wound roll 11. Again, the spacing shown in FIGURE 2 is exaggerated for purposes of simplifying the view.

It will be noted that the underwinder drum assembly 24 comprises a pair of closely spaced uniplanar rollers 24a, 24b and mounting means in the form of the frame 240 maintaining such uniplanar rollers 24a, 24b in a plane rP-P generally tangential to the wound roll 21 during the windup of the sheet 2111. As will be appreciated, the rolls 24a and 24b are mounted for rotation about their axes 24d and 242, respectively, on the frame 24c. The axes 24d and 242 are generally parallel and, .of course, as such lie in the same plane indicated in short dashed lines at p-p. The rollers themselves, 24a and 2411 are likewise uniplanar or lying in the same plane, which is here considered as the plane P-P of contact with the wound roll 21. This plane of contact P-P is maintained generally tangential to the wound roll 21 by virtue of a pivotal mounting of the frame 24c indicated at 24 which permits limited tilting of the frame 240 to accommodate changes in diameter of the Wound roll 21 during 'windup. Drive means indicated diagrammatically at 24g are rotatably mounted on the frame member 24c [for driving the rollers 24a and 24b, as indicated by the arrows in dotted lines.

In addition, resilient means are interposed between the rollers 24a and 24b and the wound roll in the form of a looped belt 24h encircling the rollers 24a and 24b within its loop. There is also mounted on the frame 24c means for applying tension to the belt 24/1 in the form of a rtensioning roller 24f freely rotatable about an axis 24k, adjustably positioned by means indicated generally at 24m. The adjusting means 24111 are conventional means for adjustably positioning the tensionin-g roll 24 toward and away from the wound roll 21 and the rollers 24a and 24b supporting the same. The tensioning roller 24 is, of course, used to vary the tension on the belt 24h and thus impart a resilient effect to the manner in which the belt 24h cooperates with the rollers 24a and 24b to support the wound roll 21.

As indicated in FIGURE 2, if a conventional underwinder tdrum were used in place of the assembly 24, there would be an approximate area A1 or line of contact between the underwinder drum and the wound roll 21, at which approximately one-half of the weight of the Wound roll 21 is supported. In contrast, in the underwinder drum assembly 24 using the proper tension on the belt 24h, the area of contact is greatly enlarged to the area A-2 indicated in FIGURE 2. This results in a very substantial decrease in the pressure in pounds per unit area that the underwinder assembly 24 actually exerts against the wound roll 21 at any given moment in the windup operation (as compared to the pressure per unit area in the case of the limited area of contact A-l involved using a single underwinder drum :of the prior art).

As indicated in FIGURE 2, the area of contact A-Z between the wound roll 21 and the belt 2411 may be an area of substantially uniform force throughout, if the tension on the belt 2411 is at a predetermined value, but otherwise this is not necessarily so. Of course, the belt 24h is preferably made :of a material that is more resilient than the rigid metal underwinder rollers 24a, 24b. This resilience within the belt itself will, of course, effect a slight enlargement in the load supporting area in the immediate region of the two rollers 24a and 2412, even if there is no appreciable tension on the belt 24h. As the tension is increased on the belt 2411, however, the load carrying area increases until it finally reaches the full dimension of the area A-Z. It will be appreciated further, however, that if the tension on the belt 24h is increased beyond this point (and the belt 2411 is not so resilient that it yields completely), then the total area carrying the weight of the wound roll 21 decreases away from the regions immediately adjacent the rollers 24a and 24b and toward a region of the belt reach 24h between the rollers 24a, 24b that is approximately intermediate. It will further be noted that as the weight of the wound roll 21 increases, its size increases and the frame 24c is caused to tilt clockwise. The tension adjusting means 24m for the belt 24h may be controlled by means 2 in responsive to the tilting of the frame 240. In other words, a given predetermined tension on the belt 24h for a given weight on the wound roll 21 may result in an effective increase in the load carrying area to the area indicated at A-Z in FIGURE 2. As the weight of the wound roll 21 increases, however, this same tension on the belt 24h is no longer capable of maintaining an area A2 of substantially uniform force throughout and, if this condition of uniform force is desired, (then it becomes necessary to increase the tension on the belt 24h. At the same time, the increase in weight of the wound roll 21 has effected an increase in size thereof and thus a clockwise tilting of the frame 24c. Suitable control means 24n which are thus responsive to the tilting of the frame 240 (and also responsive to the increase in the weight of the roll 21) may be used to control the increase in the tension in the belt 24h in a predetermined manner.

As indicated previously, the theoretical line of contact using a rigid underwinder drum would be extremely narrow in the absence of any appreciable load, but as the Weight of the wound roll 21 increases to substantial magnitude, the inherent resilience of the outer portions of the paper on the wound roll 21 would effect the formation of a somewhat wider area of contact A-1; but this area of contact A-I would still be limited to a relatively narrow region because of the rigid surface characteristics of the conventional underwinder drum 14. In contrast, the assembly 24 (and the unit FIGURE 3 which will be described later) results in a distribution of the weight of the wound roll 21, or the weight carried by the assembly 24, over a substantially greater area which may be as great as A-Z with adjustment of the tension on the belt 24h to the desired tension. This, in turn, results in a reduction of the force per unit area against any given area of the surface of the wound roll 21, compared with that obtained with the conventional prior art underwinder drum. The increase in load supporting area from the conventional line of contact area A-l to the area of contact (cg. A-2) in the case of the instant invention should be by a factor of at least about 2 or 3 times and is preferably by a factor of or more times. This rather substantial increase in area of contact also greatly minimizes the potentially harmful application of forces to the periphery of the wound roll 21 resulting from the driving of the same (as compared to driving of the conventional underwinder drum).

It will be noted that the underwinder assembly 23 need not be equipped with drive means, but otherwise functions in substantially the same manner as the underwinder assembly 24 functions with the parts thereof indicated in the 23 series of reference numerals with the correspond- 6 ing reference letter of the alphabet. Thus, the rollers 23a and 23b support their share of the weight of the wound roll 21, via the belt 23h and they are likewise mounted in a frame 23c rotatably carried on a fixed pivot 23 lying in substantially the same horizontal plane as the fixed pivot 24- rotatably mounting the assembly 24.

Referring now to FIGURE 3, which shows another embodiment of the invention indicated generally by the reference numeral 3% it will be seen that there is shown fragmentarily a wound roll 31 that is wound from a traveling web 31a, traveling about one of a pair of allochiral underwinder drum assemblies indicated generally by the reference numeral 34. The underwinder drum assembly comprises a pair of closely spaced rollers 34a and 34b carried by a frame 340 and rotatably mounted about their axes 34d and 34e, respectively. The frame 340 is mounted on a fixed pivot means 34 to permit tilting movement thereof. The rollers 34a and 34b are preferably equipped with resilient solid elastomeric coverings so as to increase the individual areas of contact for each, but an important feature of the assembly 34 is that the rollers 34a and 341; are closely spaced. As a practical matter, the rollers 34a and 34.11 are more closely spaced than is indicated in FIGURE 3 (with the spacing shown in FIGURE 3 in exaggerated manner for simplification of the showing). As indicated previously, there is a local compacting effect in the peripheral portion of the paper on the wound roll 31 resulting from the contact between the conventional underwinder drum 14 and a wound roll, which is referred to as the pressure wave P-l in FIGURE 1. This pressure wave, of course, extends :sorne distance on both sides of the theoretical line of contact 1-1 and extends into the conventional wound roll 11 at a peak or maximum distance approximately opposite the theoretical line of contact L-l. In contrast, in the embodiment 36 of FIGURE 3, the overall area of contact is increased so that peak loads or pressures are reduced and also the closely adjacent rollers 34a and 3412 result in a pressure wave of greater area and less intensity as indicated diagrammatically in dotted lines at the region R-I of FIGURE 3.

It will also be apparent that significant improvement over the prior art arrangement also may be achieved by use of one allochiral assembly 24 or 34 in place of one of the single rolls 14 or 13. Furthermore, the assembly '23 could be advantageously combined with the assembly 34.

It will be understood that modifications and variations may be effected without departing from the spirit and scope of the novel concepts of the present invention.

I claim as my invention:

1. In a device for winding a traveling sheet upon itself to form a wound roll, -a plurality of spaced underwinder drum assemblies adapted to support the wound roll from beneath, at least one of said assemblies comprising a pair of closely spaced uniplanar rollers and mounting means maintaining such uniplanar rollers in a plane generally tangential to said wound roll during windup of the sheet, each of said rollers creating a local compacting pressure wave in the roll, said rollers of each pair being spaced suificiently close so that their pressure waves overlap and the intensity of the pressure waves is reduced and whereby the area supporting the weight of the wound roll via said pair of rollers is increased beyond that of the normal line of contact between a single underwinder drum and the wound roll, and means for guiding the traveling sheet through said area for effecting winding of such sheet into the wound roll.

2.. In a device for winding a traveling sheet upon itself to form a wound roll, a plurality of spaced underwinder dnu-m assemblies adapted to support the wound roll from beneath, each of said assemblies comprising a pair of closely spaced uniplanar rollers, resilient means interposed between said rollers and the wound rolls and mounting means maintaining such uniplanar rollers in a plane generally tangential to said Wound roll during windup of the sheet, each of said rollers creating a local compacting pressure wavein the roll, said rollers or" each pair being spaced sufiiciently close so that their pressure waves overlap and the intensity of the pressure waves is reduced and whereby the area supporting the weight of the wound roll via said pair of rollers is increased beyond that of the normal line of contact between a single underwinder drum and the wound roll, and means for guiding the traveling sheet through said area for eltecting winding of such sheet into the wound roll.

3. In a device for winding a traveling sheet upon itself to form a wound roll, a plurality of spaced underwinder drum assemblies adapted to support the wound roll from beneath, each of said assemblies comprising apair of closely spaced uniplanar rollers, a looped belt encircling said rollers and interposed between said rollers and the wound roll, mounting means maintaining such uniplanar rollers in a plane generally tangential to said wound roll during windup of the sheet, and means controllably tensioning said belt so that the proportion of total force between the belts and roll at the center of the span of belt between said rollers and at the ends of said span may be varied, whereby the area supporting the weight of the wound roll via said pair of rollers is increased beyond that of the normal line of contact between a single underwinder drum and the Wound roll, and means for guiding the traveling sheet through said area for effecting winding of such sheet into the wound roll.

4. Ina device for winding a traveling sheet upon itself to form a wound roll, a plurality of spaced underwinder drum assemblies adapted to support the wound roll from beneath, each of said assemblies comprising a pair of closely spaced uniplanar rollers, a looped bel-t encircling said rollers and interposed between said rollers and the wound roll, means applying tension to said belt and mounting means maintaining such uniplanar rollers in a plane generally tangential to said Wound roll during windup of the sheet, said tensioning means being controllably variable so that the proportion of total force between the belts and the roll at the center of the span of belt between the rolls and the ends of said span may be varied, whereby the area supporting the weight of the wound roll via said pair of rollers is increased beyond that of the normal line of contact between a single under- Winder drum and the wound roll, and means for guiding the traveling sheet through said area for etfecting winding of such sheet into the Wound roll.

5. A winding device for a traveling paper Web, that comprises core means for winding the web upon itself to form a wound roll, two separate pairs of closely spaced rollers supporting the wound roll from beneath, separate looped belts encircling each of said pairs of rollers, separate tensioning means for each of said belts for maintaining separate reaches of the belts between each pair of rollers in contact with said wound roll for carrying the weight of the wound roll substantially throughout the areas of said reaches, said tensioning means being controllably variable so that the proportion of total force between the belts and roll at the center of said belt reach and at the ends of said reach may be varied, and separate mounting means rotatably carrying each of said pairs of rollers maintaining the same in planes generally tangential to said wound roll during windup'.

6. A winding device for a traveling paper web, that comprises core means for winding the web upon itself to form a wound roll, two separate pairs of closely spaced rollers supporting the wound roll from beneath, separate looped belts encircling each of said pairs of rollers, sep arate tensioning means for each of said belts for maintaining separate reaches of the belts between each pair of rollers in contact With said wound roll for carrying the weight of the wound roll substantially throughout the areas of said reaches, said tensioning means being controllably variable so that the proportion of total force between the belts and roll at the center of said belt reach and at the ends of said reach may be varied, drive means for one pair of said rollers for driving the wound roll during windup, and separate mounting means rotatably carrying each of said pairs of rollers and maintaining the same in planes generally tangential to said wound roll during windup.

7. A winding device for a traveling paper web, that comprises core means for Winding the web upon itself to form a Wound roll, two separate pairs of closely spaced rollers supporting the wound roll from beneath, separate looped belts encircling each of said pairs of rollers, separate tensioning means for each of said belts for maintaining separate reaches of the belts between each pair of rollers in contact with said wound roll for carrying the Weight of the wound roll substantially throughout the area of said reaches, said tensioning means being controllably variable so that the proportion of total force between the belts and roll at the center ofsaid belt reach and at the ends of said reach maybe varied, means feeding the traveling Web to the wound roll between said two separate pairs of rollers, and separatemounting means rotatably carrying each of said pairs of rollers and maintaining the same in planes generally tangential to said wound roll during windup.

References Cited in the file of this patent UNITED STATES PATENTS 1,078,099 Kremer Nov. 11, 1913 2,285,358 Rode et a1. June 2, 1942 2,327,263 Heath et al Aug. 17, 1943 FOREIGN PATENTS 417,769 Great Britain Oct. 11, 1934 535,817 Belgium Mar. 15, 1955 

1. IN A DEVICE FOR WINDING A TRAVELING SHEET UPON ITSELF TO FORM A WOUND ROLL, A PLURALITY OF SPACED UNDERWINDER DRUM ASSEMBLIES ADAPTED TO SUPPORT THE WOUND ROLL FROM BENEATH, AT LEAST ONE OF SAID ASSEMBLIES COMPRISING A PAIR OF CLOSELY SPACED UNIPLANAR ROLLERS AND MOUNTING MEANS MAINTAINING SUCH UNIPLANAR ROLLERS IN A PLANE GENERALLY TANGENTIAL TO SAID WOUND ROLL DURING WINDUP OF THE SHEET, EACH OF SAID ROLLERS CREATING A LOCAL COMPACTING PRESSURE WAVE IN THE ROLL, SAID ROLLERS OF EACH PAIR BEING SPACED SUFFICIENTLY CLOSE SO THAT THEIR PRESSURE WAVES OVERLAP AND THE INTENSITY OF THE PRESSURE WAVES IS REDUCED AND WHEREBY THE AREA SUPPORTING THE WEIGHT OF THE WOUND ROLL VIA SAID PAIR OF ROLLERS IS INCREASED BEYOND THAT OF THE NORMAL LINE OF CONTACT BETWEEN A SINGLE UNDERWINDER DRUM AND THE WOUND ROLL, AND MEANS FOR GUIDING THE TRAVELING SHEET THROUGH SAID AREA FOR EFFECTING WINDING OF SUCH SHEET INTO THE WOUND ROLL. 